Chief Commissioner Graham Ashton on Sunday said police were keeping tabs on the extremists, particularly online.

"After Friday we have intensified our monitoring of the alt-right individuals within Victoria," Mr Ashton said.

Victoria Police Chief Commissioner Graham Ashton said dozens of right wing extremists are on terror watchlists.

"We've been monitoring also a range of individuals since Friday, we're just making sure we're not seeing any increased levels of anxiety around any sort of action and certainly to date we haven't seen that."

Mr Ashton said he spoke with his federal counterpart about monitoring online rhetoric that might constitute a federal offence.

"These threats can emerge very quickly and often from very little information or intelligence beforehand," he said.

"You do the best you can, we make sure we're plugged into what's happening in the intelligence arena, particularly with our federal partners."

Mr Ashton was at Preston Mosque on Sunday alongside Premier Daniel Andrews as part of a pre-organised, statewide open mosque day.

Anti-immigration white nationalists violently leapt on a teenager who egged Queensland Senator Fraser Anning at an event in suburban Melbourne on Saturday.

Victorian Premier Daniel Andrews headed to Preston Mosque on Sunday as part of an open day in the wake of the NZ attack.

Among them was convicted criminal Neil Erikson who is currently going through the courts again.

Mr Ashton said he's directed his officers to go through footage of the incident in its entirety to consider whether assault charges and breach of bail offences might also come into play.